Safe scaffold structure with guardrails

ABSTRACT

A safe scaffold includes door type frames, crossbars, and toe boards. The door type frame has a ledger, located in the lower end, connected to standards that are parallel to each other and are installed with combined pins thereon individually. The crossbar includes joint bar members having engaging holes engaged with the combined pins of the door type frame, and connects one door type frame to another door type frame in a cross link method, or connected to other joint bar members through the engaging couplers. The toe board is provided on the ledgers of every two adjacent door type frames. The invention creates an available space for setting guardrails by lowering the position of the toe board of the scaffold, adjusts the position and combination of the crossbars to form guardrails, and reduces the gaps of side rails.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to scaffolds and more particularly to a safescaffold structure with guardrails.

2. Description of Related Art

Currently, the scaffold available in the market usually has a mainstructure comprising door type frames, crossbars and a toe board. Thedoor type frame consists of the part of vertical standards and the partof ledger that is connected to two standards. The crossbar is aconnecting element having combined pin holes on both ends. The part ofvertical standard of the door type frame has combined pins that can bejointed to pin holes of the crossbars. Therefore, when the pin holes onboth ends of the crossbar are joint with the combined pins of two doortype frames separately, the function of connecting two door type framesis achieved. Once the toe board is added on, the structure elements of ascaffold is completed.

The scaffold commonly used currently has the ledgers set on the upperpart of the standards mostly. Besides, the ledgers of the door typeframe are usually used for the toe board to rest thereon. Therefore,when the scaffold is constructed, the toe board is placed on the upperpart of the scaffold. When a worker stands on the toe board, if oneadditional layer of scaffold is not constructed on top of the existingone, the worker then has no guardrail to hold on to and the settingbecomes dangerous.

Therefore, according to the current regulations on “the scaffoldadvancing guardrail method”, to construct a scaffold that reaches aheight of over 2 meters above the ground, it is required to firstinstall fall protection equipments. In other words, a rack and anadvancing guardrail frame are installed on the upper part of the doortype frame as the protection rail of composing the third layer ofscaffold before the construction of scaffolds is allowed to continue,making the procedure of constructing a scaffold very complicated.

Please refer to FIG. 1 for the scaffold of prior art. According to thefigure, the scaffold 1′ of prior art, the toe board 13 is provided atthe position above the center of the structure of the door type frame11′ of prior art. In addition, the crossbars of prior art 12′ is beneaththe toe board 13. When the construction worker steps on the toe board,there are no fall protection equipments on the side rails and it is veryrisky and dangerous.

Therefore, in the construction process of prior art, in order to complywith the safety regulations of “the scaffold advancing guardrailmethod”, the scaffold 1′ of prior art is first installed with the fallprotection equipment onto the upper layer of the structure thereof.

Please refer to FIG. 2A to FIG. 2F for detail information. The processof constructing the fall protection equipment of the scaffold isdiscussed below:

Install the top layer of the door type frames: In FIG. 2A, theinstallation position of the door type frame 11′ of prior art isprovided on the door type frame 11′ of prior art of the lower layer ofthe scaffold.

Install the rack of the fall protection equipment: According to FIG. 2B,the installation location of the rack 2 is located in between twoadjacent layers of scaffolds.

Install the protective guardrail of the fall protection equipment:According to FIG. 2C, the advancing guardrail frame 3 is provided on therack outer side the scaffold 1′ of prior art.

Install the toe board on the scaffold of the top layer: According toFIG. 2D, with the protective guardrail of the top layer in place,install the toe board 13 on the scaffold of the top layer.

Install the crossbar of the scaffold of the top layer: According to FIG.2E, the crossbar 2′ of prior art is installed on the inner side of theadvancing guardrail frame 3.

Remove the protective guardrail: According to FIG. 2D, when the scaffold1′ of prior art of the top layer is constructed completely, theadvancing guardrail frame 3 will be removed first (as illustrated inFIG. 2E); the steps of constructing another top layer of scaffold, asshown in FIG. 2A, is repeated again.

The aforementioned construction of the scaffold is performed incompliance with “the advancing guardrail method” to increase the safetyof the high altitude scaffold. However, since there are too many partsto assemble and the steps are is tedious and time consuming, the timefor the high altitude operation is prolonged, resulting in higher riskof danger.

When the scaffold is completed, to ensure the safety of construction andto prevent construction workers from falling due to sudden impairment offunction, every country is working hard to include safety relatedcomponents to reduce the risk that a worker may fall, as shown in FIG.3A to FIG. 3C.

With reference to FIG. 3A to FIG. 3C, the diagrams illustrate the safetymeasure applied to scaffold 1′ of prior art during the construction. Asshown in FIG. 3A, an additional horizontal bar 4 is installed as amethod to reduce the gap of side rails G′; in FIG. 3B, an additionalkick board 5 is installed as a method to reduce the gap of side railsG′; in FIG. 3C, an additional horizontal bar 4 and an additional kickboard 5 are installed as a method to reduce the gap of side rails G′.

Please refer to FIG. 4A and FIG. 4B, first lower the ledger 111 of thedoor type frame 11′ of prior art: The center of gravity of the door typeframe 11 descends accordingly. In addition, the toe board 13 (asillustrated in FIG. 1) installed on the ledger 111 descends to theposition below the center of the door type frame 11 so that the sectionof the standard 112 of the door type frame 11 above the position of theledger increases, serving the effect of a handrail.

Adjust the location of combined pin 113: The combined pin 113 in thelower part is provided below the location of the ledger 111.

With reference to the scaffold 1′ of prior art shown in FIG. 4B, aschematic diagram of the door type frames 11′ of prior art used to buildthe upper layer of the scaffold 1′ of prior art is shown. From thediagram, the center of gravity of the door type frame 11′ of prior artis located above the center point. Therefore, when the constructionworker lifts the door type frame during the construction, the moment armX′ from the location, where the construction worker holds, to the centerof gravity of the door type frame 11′ of prior art increases.

However, these methods of installing additional safety components havethe same shortcoming as the other aforementioned method that adopts thefall protection equipments during construction, that is, much moreassembly steps due to the additional components to be installed duringconstruction, longer time for high altitude operation and, as a result,a higher risk of danger.

However, the objective of the so-called “the advancing guardrail” is toimprove the safety of the construction workers. Nevertheless, in orderto install the equipment of fall prevention, the duration of highaltitude operation lengthens and the procedure becomes complicated, as aresult, causing the risk of danger to increase unexpectedly.

Thus, the need for improvement still exists.

SUMMARY OF THE INVENTION

It is therefore one object of the invention to provide a scaffoldcomprising door type frames; crossbars; and toe boards; wherein the doortype frames use ledgers to connect a plurality of standards that areparallel to each other and are installed with combined pins thereonindividually; wherein each of the crossbar include a plurality of jointbar members having engaging holes thereon, which can be engaged with thecombined pins of the door type frames, and connect one door type frameto another door type frame in a cross link or be connected to otherjoint bar members through the engaging couplers; and wherein the toeboards are provided on the ledgers of every two adjacent door typeframes.

The above and other objects, features and advantages of the inventionwill become apparent from the following detailed description taken withthe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective schematic diagram of a scaffold of prior art;

FIG. 2A is a schematic diagram of steps of constructing a scaffold ofprior art;

FIG. 2B is a schematic diagram of steps of constructing a scaffold ofprior art;

FIG. 2C is a schematic diagram of steps of constructing a scaffold ofprior art;

FIG. 2D is a schematic diagram of steps of constructing a scaffold ofprior art;

FIG. 2E is a schematic diagram of steps of constructing a scaffold ofprior art;

FIG. 2F is a schematic diagram of steps of constructing a scaffold ofprior art;

FIG. 3A is a schematic diagram of safety implementation method of ascaffold of prior art;

FIG. 3B is a schematic diagram of safety implementation method of ascaffold of prior art;

FIG. 3C is a schematic diagram of safety implementation method of ascaffold of prior art;

FIG. 4A is a schematic diagram of a door type frame of prior art;

FIG. 4B is a schematic diagram of steps of constructing a door typeframe of a scaffold of prior art;

FIG. 5A is a schematic diagram of an improved door type frame of theinvention;

FIG. 5B is a schematic diagram of steps of constructing a door typeframe of a safe scaffold structure with guardrails of the invention;

FIG. 6A is a schematic diagram of a crossbar;

FIG. 6B is a schematic diagram of two crossbars joined;

FIG. 6C is a schematic diagram of the joined crossbars being furtherextended;

FIG. 7A is a schematic diagram of steps of constructing a safe scaffoldstructure with guardrails of the invention;

FIG. 7B is a schematic diagram of steps of constructing a safe scaffoldstructure with guardrails of the invention;

FIG. 7C is a schematic diagram of steps of constructing a safe scaffoldstructure with guardrails of the invention; and

FIG. 8 is a perspective schematic diagram of a safe scaffold structurewith guardrails of the invention.

DETAILED DESCRIPTION OF THE INVENTION

A safe scaffold structure with guardrails of the invention is to improvethe complex procedure and construction duration due to the need ofadding additional safety equipment, in order to effectively reduce thetime required for high altitude operation, to lower the risk of danger,and to increase the safety during the construction.

Referring to FIG. 5A and FIG. 5B together, a door type frame 11 of theinvention is shown. The center of gravity of the door type frame 11descends so that the safety on constructing the door type frame 11increases. A toe board 13 installed on the ledger 111 descends to theposition below the center of the door type frame 11 so that the sectionof the standard 112 of the door type frame 11 above the position of theledger 111 increases, serving the effect of as a handrail.

Adjustment of the location of combined pin 113: The combined pin 113 inthe lower part is provided below the location of the ledger 111. In thisembodiment, for example, the combined pin 113 is located between theledger support structure 1111 and the ledger 111. It can effectivelyreduce the scale of the gap of side rail of the conventional scaffoldand increase safety.

For increasing safety, it is preferred to move the center of gravity ofthe door type frame 11 downward. In comparison with the prior art, thetorque of the door type frame of prior art is greater than the torque Mof the door type frame 11. Thus, using the door type frame 11, the stepsof constructing the door type frame 11 is much safer.

Referring to FIGS. 6A, 6B and 6C, in this embodiment, a crossbar 12includes a joint bar member 121 having three sections. The joint barmember 121 is used to couple the combined pin 113 of the door type frame11, resulting in a joint between a door type frame 11 and another doortype frame 11. The joint bar member 121 has engaging holes 122 for thecombined pin 113 to mount through, and is joined another joint barmember 121 through an engaging coupler 123.

The construction process of the safe scaffold structure with guardrailsof the invention can achieves goal of preventing accidental fall whileeliminating the installation of the fall protection equipment.

Referring to FIG. 7A to FIG. 7C, in FIG. 7A, door type frames 11 of thetop layer is installed: As described in FIG. 5A and FIG. 5B, as thecenter of gravity of the improved door type frame 11 descends, themoment bar X from center of gravity of the door type frame 11 to theposition where the construction worker holds is shortened. Therefore,when another top layer of door type frame 11 is disposed again, theconstruction worker can control the process more easily andcomparatively safer.

In FIG. 7B, the crossbars 12 of the top layer is installed: Adjustingthe location where the door type frame 11 is joined the combined pin 113allows the construction worker to join the engaging hole of the crossbar12 to the combined pin 113 of the door type frame 11 while standing onthe structure of the lower layer and, as a result, creates the effect ofa protection rail.

In FIG. 7C, the toe board 13 of the top layer is installed: The toeboard 13 is installed last. According to the figure, the gap of siderail G between the toe board 13 and the crossbars 12 is smaller than thegap of side rail G′ of the scaffold 1′ of prior art shown in FIG. 3A toFIG. 3B.

Referring to FIG. 8, it is a perspective schematic diagram of a safescaffold structure with guardrails of the invention. The crossbars 12are disposed between the door type frame 11 and the adjacent door typeframe 11 to cross link and fix together. The toe board 13 is placed onthe ledgers 111 of the door type frames 11. The gap of side rail Gformed between the toe board 13 and the crossbars 12, compared to thegap of side rail G′ of the scaffold 1′ of prior art, it is significantlydecreased so as to greatly increase safety.

While the invention has been described in terms of preferredembodiments, those skilled in the art will recognize that the inventioncan be practiced with modifications within the spirit and scope of theappended claims.

What is claimed is:
 1. A scaffold, comprising: door type frames;crossbars; and toe boards; wherein the door type frames use ledgers toconnect a plurality of standards that are parallel to each other and areinstalled with combined pins thereon individually; wherein each of thecrossbar include a plurality of joint bar members having engaging holesthereon, which can be engaged with the combined pins of the door typeframes, and connect one door type frame to another door type frame in across link or be connected to other joint bar members through theengaging couplers; and wherein the toe boards are provided on theledgers of every two adjacent door type frames.
 2. The scaffold asclaimed in claim 1, wherein the joint method between the ledger and thestandard of the door type frame is a soldering joint.
 3. The scaffold asclaimed in claim 1, wherein the joint method between the ledger and thestandard of the door type frame is a pin mount.
 4. The scaffold asclaimed in claim 1, wherein a ledger support structure is installedbelow the ledger.
 5. The scaffold as claimed in claim 4, wherein theledger support structure is a circular arc shaped support structure. 6.The scaffold as claimed in claim 4, wherein the ledger support structureis an inverted V shaped support structure.
 7. The scaffold as claimed inclaim 1, wherein the door shape frame is a heavy-duty support frame. 8.The scaffold as claimed in claim 1, wherein the door shape frame is asteel tube construction support frame.
 9. The safe scaffold structurewith guardrails as claimed in claim 1, wherein the door shape frame is amobile scaffold.
 10. The scaffold as claimed in claim 1, wherein thecrossbar includes three sections of joint bar members.
 11. The scaffoldas claimed in claim 1, wherein the crossbar includes two sections ofjoint bar members.
 12. The scaffold as claimed in claim 1, wherein theengaging coupler is a fixed engaging coupler.
 13. The scaffold asclaimed in claim 1, wherein the engaging coupler is a detachableengaging coupler.